Isolated human genes can be patented, US court rules

Good for DNA research, but could lead to overpriced diagnostics

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Isolating genes from human DNA structures is patentable, the US Court of Appeals has ruled.

The Court ruled that the process of isolating genes from human DNA strands left the resultant individual genes with "markedly different chemical structure" from DNA in the human body.

US patent law says that material related to laws of nature cannot be patented. Inventions must also be new, take an inventive step that is not obvious and be useful to industry to qualify for patent protection.

"The ability to visualise a DNA molecule through a microscope, or by any other means, when it is bonded to other genetic material, is worlds apart from possessing an isolated DNA molecule that is in hand and usable," the US Court of Appeals ruling (105-page/684KB PDF) said.

"It is the difference between knowledge of nature and reducing a portion of nature to concrete form, the latter activity being what the patent laws seek to encourage and protect," the ruling said.

The decision reverses a decision (156-page/859KB PDF) by a district court in New York that had ruled isolated human DNA molecules could not be patented.

Medical testing company Myriad Genetics had identified two gene sequences, BRCA1 and BRCA2, which were linked to breast cancer. The US District Court for the Southern District of New York had said that patents the company held over them were "improperly granted" by the US Patent and Trademark Office.

Myriad had argued that it was the method of isolating the gene and not the gene itself that was the subject of its patent. Myriad appealed and in a majority decision the Court ruled that the company could patent isolated genes.

The ruling went against Myriad's opponents, which included the Association for Molecular Pathology and the American College of Medical Genetics. They had argued that the isolated genes were laws of nature and not therefore not patentable. The genes Myriad isolated contained the same molecules as collective human DNA strands, they said.

The Court of Appeals said it was the "distinctive nature" of individual genes "as isolated compositions of matter" that could make them patentable. Patent eligibility should not be determined by the isolated genes' "physiological use or benefit," it said.

Myriad used chemicals to split the genes from the DNA structures and this creates a "distinct chemical entity", the Court said in its ruling.

"Uses of chemical substances may be relevant to the non-obviousness of these substances or to method claims embodying those uses, but the patent eligibility of an isolated DNA is not negated because it has similar informational properties to a different, more complex natural material that embodies it," the ruling said.

"The claimed isolated DNA molecules are distinct from their natural existence as portions of larger entities, and their informational content is irrelevant to that fact. We recognise that biologists may think of molecules in terms of their uses, but genes are in fact materials having a chemical nature and, as such, are best described in patents by their structures rather than their functions," the ruling said.

"In this case, the claimed isolated DNA molecules do not exist as in nature within a physical mixture to be purified. They have to be chemically cleaved from their chemical combination with other genetic materials. In other words, in nature, isolated DNAs are covalently bonded to such other materials. Thus, when cleaved, an isolated DNA molecule is not a purified form of a natural material, but a distinct chemical entity. In fact, some forms of isolated DNA require no purification at all, because DNAs can be chemically synthesised directly as isolated molecules," it said.

The ruling is likely to be challenged, but this decision of the Court of Appeals will please companies in the US genetics industry, according to one patent law expert.

"Those with a vested interest in the commercialisation of human genetics argue that the ability to obtain patent protection encourages investment in DNA research, which serves to further innovation. Those opposed to what is perceived to be the monopolisation of nature fear that the high cost of diagnostic testing, such as Myriad's tests for breast cancer will price many out of the market. The Court's reasoning appears dubious and an appeal is inevitable. On both sides of the fence this case will be watched with interest," Bloom said.